Author Topic: Question about tightening the timing belt (Read 6632 times)

silvertdi · « **on:** June 25, 2008, 04:27:44 pm »

If I tighten the timing belt slightly, do I need to re-time the IP? Thanks.

silvertdi · « **Reply #1 on:** June 26, 2008, 03:56:07 am »

Someone must know the answer.

myke_w · « **Reply #2 on:** June 26, 2008, 04:30:12 am »

yea you can get away with that, just don't go too tight.

burn_your_money · « **Reply #3 on:** June 26, 2008, 04:53:31 am »

Why do you think you need to tighten it?

It will throw everything off, so at least check everything

myke_w · « **Reply #4 on:** June 26, 2008, 05:03:13 am »

I was thinking about it in terms of pump timing, working under the assumption that the belt has stretched. If that's the case - tightening it to spec actually should bring it back to initial timing spec. It's never a bad idea to recheck of course.

silvertdi · « **Reply #5 on:** June 26, 2008, 07:30:49 pm »

I'll try to explain what's happening. When I'm cruising at highway speeds, the engine feels like it's firing on three cylinders. A funny sounding/feeling kind of miss. The moment I slightly depress the accelerator, it clears up and begins to pull. I figured the timing might be drifting as its been 50k miles since I've changed it. The fuel mileage has also gone down slightly to around 40 mpg. Any suggestions?

theman53 · « **Reply #6 on:** June 27, 2008, 06:43:08 pm »

My rabbit is doing this also and after lots of fighting and noticing a leaky pump I am guessing and hoping and am pretty darn sure that this new ULSD is my problem. Since the ULSD I have lost 15 to 20 percent in fuel economy and my pump leaks. I need a new pump because of this. I could be wrong but I think it is your problem as well. I don't know if you have replaced the injectors, fuel filter, air filters, IP timing and held your mouth just right but I have and no difference.

burn_your_money · « **Reply #7 on:** June 28, 2008, 06:11:30 am »

Your timing shouldn't drift, and if that is what you suspect stop driving immediately and get it checked out. Tightening the belt is not going to solve anything.

silvertdi · « **Reply #8 on:** June 28, 2008, 10:20:25 am »

Took off the timing belt cover and checked the belt tension. It looks good. Just as I left it. My pump was rebuilt by the previous owner. It doesnt leak, but I get air bubbles in the line every now and then.

Golf/Jetta · « **Reply #9 on:** February 01, 2009, 02:05:50 pm »

those air bubbles are some what normal. it happens when fuel is being pulled. its funny that it doesn't leave the pump but more gets sucked in..

8v-of-fury · « **Reply #10 on:** February 01, 2009, 05:10:44 pm »

Quote from: "Golf/Jetta"

those air bubbles are some what normal. it happens when fuel is being pulled. its funny that it doesn't leave the pump but more gets sucked in..

Wow. lol since when does pulling a liquid make a gas appear? They go in and don't come out of the pump because your engine is ingesting them. You'll notice your car will run like complete *** when there is bubbles present. The bubbles are there because you have a leak in your fuel line somewhere and air is lighter and less dense than diesel, thus making it get sucked in through the leak and in to the engine. You my friend, have made me entire weekend that much more funny. :lol:

jtanguay · « **Reply #11 on:** February 01, 2009, 05:13:55 pm »

a few bubbles in the line is okay maybe when you rev the motor hard. okay, but not 'right'.

bubbles in the line are an indication that one of the lines is allowing air into the system. the pump should be sucking from the bottom of the fuel tank, and therefore no air should get in. possibly culprits are the check valve, water separator, and fuel lines themselves. now if the check valve is bad, the pump will have to suck harder to get the fuel moving. this will put more vacuum on the line and some air might actually get sucked in from the fuel line connections if they're old and cracked.

Rabbit TD · « **Reply #12 on:** February 01, 2009, 07:20:13 pm »

Quote from: "theman53"

My rabbit is doing this also and after lots of fighting and noticing a leaky pump I am guessing and hoping and am pretty darn sure that this new ULSD is my problem. Since the ULSD I have lost 15 to 20 percent in fuel economy and my pump leaks. I need a new pump because of this. I could be wrong but I think it is your problem as well. I don't know if you have replaced the injectors, fuel filter, air filters, IP timing and held your mouth just right but I have and no difference.

I have been running my N/A Rabbit on ULSD for close to a year now, {was using furnace oil before} and I'd say I have about 8,000 on it using the new fuel and have not noticed anything different yet. I put a new shaft seal in the pump about 2 years ago and have been watching it pretty closely for leaks and so far so good and I don't use any constant additive, just some ATF about every 5 or so tanks and my mileage is still as good as ever, I really believe it is even better than ith the heating oil. I always wondered other than the seals designed for ULSD what could they have possibly done to the internals of the newer pumps to make them safe for the new fuel with less lubricant. Don't the tolerances still have to be the same and such and what kind of metal could they possibly be using that requires less lubrication. One story I read about this was in the beginnig when they started taking out the sulpher there was supposed to be a lubricant added to replace the lubricating properties the sulpher had. The problem from what I read as that it was up to the distributor and not the refinery to replace this and not all distibutors were doing this on a consistent basis with each other or in some cases at all and that is where the majority of the early pump problems came from and may still be depending where the fuel comes from.
This is just an article I found a while back researching this problem with pumps and I don't even remember where I read it for that matter and don't know if there is any truth to it or not but it does kind of make sense. I know around here I haven't really heard of any problems at all with the LSD or ULSD so maby we are getting the lubricant that is supposedly being added and the correct amount. Maby Andrew or one of the people with pump experience can shed some light on this as to what has changed inside the new pumps to require less lubrication if in fact any major changes other than different seal materials has been made. Myself I find it hard to believe that they could come up with a better material or treatment than what was always there to begin with to last in the lapped fit parts and such and that there is supposed to be a certain amount of luicant added to the fuel when we get it at the pump but not all refineries or distributors are following the same guidelines if in fact there are any. It kind of sounds to me like comparing gasolines, 87 octane is 87 octane no matter who is selling it but some have more and different additives for different purposes than others have. These ae just my thoughts from what I understand at this point but if somebody knows something to the contrary or more information pleae post it, I would like to know the facts myself. But I can say though that around here nobody including farmers an such seem to be having any trouble with the new stuff and it's been ULSD here for more than a year.

zukgod1 · « **Reply #13 on:** February 02, 2009, 06:53:26 am »

Quote from: "8v-of-fury"

Quote from: "Golf/Jetta"
those air bubbles are some what normal. it happens when fuel is being pulled. its funny that it doesn't leave the pump but more gets sucked in..

Wow. lol since when does pulling a liquid make a gas appear? They go in and don't come out of the pump because your engine is ingesting them. You'll notice your car will run like complete *** when there is bubbles present. The bubbles are there because you have a leak in your fuel line somewhere and air is lighter and less dense than diesel, thus making it get sucked in through the leak and in to the engine. You my friend, have made me entire weekend that much more funny. :lol:

I have no comment other than 8v-of-fury's Avatar makes me smile

RabbitJockey · « **Reply #14 on:** February 02, 2009, 02:58:32 pm »

i am curious myself how much the new fuel really hurts the pumps, i've ran 3 cars on it hard with out any issues, my dad runs it, and i know alot of the vw diesel people in my area, and i haven't heard a word about any issues with their pumps, i think if anything the new fuel just killed pumps that were already on their way out.